Professional guideline versus product label selection for treatment with IV thrombolysis: An analysis from SITS registry

Is off-label thrombolysis safe and effective in a real-life primary stroke center? A retrospective analysis of data from a 5-year prospective database

BACKGROUND

Intravenous thrombolysis (IVT) use for acute ischemic stroke (AIS) varies among countries, partly due to guidelines and product labeling changes. The study aim was to identify the characteristics of patients with AIS treated with off-label IVT and to determine its safety when performed in a primary stroke center (PSC).

METHODS

This observational, single-center study included all consecutive patients admitted to Perpignan PSC for AIS and treated with IVT and patients transferred for EVT, between January 1, 2015 and December 31, 2019. Data of patients treated with IVT according to ("in-label group") or outside ("off-label") the initial guidelines and manufacturer's product specification were compared. Safety was assessed using symptomatic intracerebral hemorrhage (SIH) as the main adverse event.

RESULTS

Among the 892 patients in the database (834 screened by MRI, 93.5%), 746 were treated by IVT: 185 (24.8%) "in-label" and 561 (75.2%) "off-label". In the "off-label" group, 316 (42.4% of the cohort) had a single criterion for "off-label" use, 197 (26.4%) had two, and 48 (6.4%) had three or more criteria, without any difference in IVT safety pattern among them. SIH rates were comparable between the "off-label" and "in-label" groups (2.7% vs. 1.1%, P=0.21); early neurological deterioration and systematic adverse event due to IVT treatment were similar in the 2 groups. "Off-label" patients had higher in-hospital (8.7% vs. 3.8%, P=0.05) and 3-month mortality rates (12.1% vs 5.4%, P<0.01), but this is explained by confounding factors as they were older (76 vs 67 years, P<0.0001) and more dependent (median modified Rankin scale score 0.4 vs 0.1, P<0.0001) at admission.

CONCLUSIONS

"Off-label" thrombolysis for AIS seems to be safe and effective in the routine setting of a primary stroke center.

Safety and early outcomes after intravenous thrombolysis in acute ischemic stroke patients with prestroke disability

BACKGROUND

There are limited data on intravenous thrombolysis treatment in ischemic stroke patients with prestroke disability.

AIM

We aimed to evaluate safety and outcomes of intravenous thrombolysis treatment in stroke patients with prestroke disability.

METHODS

We analyzed 88,094 patients treated with intravenous thrombolysis, recorded in the Safe Implementation of Treatments in Stroke (SITS) International Thrombolysis Register between January 2003 and December 2017, with available NIHSS data at stroke-onset and after 24 h. Of them, 4566 patients (5.2%) had prestroke disability, defined as a modified Rankin Scale score of 3-5. Safety outcome measures included Symptomatic Intracerebral Hemorrhage, any type of parenchymal hematoma on 24 h imaging scans irrespective of clinical symptoms, and death within seven days. Early outcome measures were 24-h NIHSS improvement (≥4 from baseline to 24 h).

RESULTS

Patients with prestroke disability were older, had more severe strokes, and more comorbidities than patients without prestroke disability. When comparing patients with prestroke disability with patients without prestroke disability, there was however no significant increase in adjusted odds for symptomatic intracerebral hemorrhage (adjusted odds ratio 0.83 (95% CI 0.60-1.15) (absolute difference in proportion 1.17% vs. 1.27%)) or for parenchymal hemorrhage (adjusted odds ratio 0.96 (0.83-1.11) (7.51% vs. 6.34%)). The prestroke disability group had a significantly lower-adjusted odds ratio for a 24-h NIHSS improvement (adjusted odds ratio 0.79 (0.73-0.85) (45.95% vs. 48.45%)) and a higher adjusted odds ratio for seven-day mortality (aOR 1.40 (1.21-1.61) (10.40% vs. 4.93%)).

CONCLUSIONS

Intravenous thrombolysis in acute ischemic stroke patients with prestroke disability was not associated with an increased risk of symptomatic intracerebral hemorrhage or parenchymal hemorrhage. Prestroke disability was however associated with a higher risk of early mortality compared to patients without prestroke disability.

Alteplase for Acute Ischemic Stroke in Patients Aged >80 Years: Pooled Analyses of Individual Patient Data

BACKGROUND/PURPOSE

Expert guidelines specify no upper age limit for alteplase for thrombolysis of acute ischemic stroke (AIS) but, until recently, European regulatory criteria restricted its use to patients aged 18 to 80 years. We performed pooled analyses of randomized controlled trial (RCT) and registry data to evaluate the benefit-risk profile of alteplase for AIS among patients aged >80 years to support a regulatory application to lift the upper age restriction.

METHODS

Individual patient data were evaluated from 7 randomized trials of alteplase (0.9 mg/kg) versus placebo or open control for AIS, and the European SITS-UTMOST registry database. Clinical outcomes, including good functional outcome (score 0-1, modified Rankin Scale day 90 or Oxford Handicap Score day 180), were evaluated in the full RCT and registry populations, and specified age-based subgroups (≤80 or >80 years) who met existing European regulatory criteria for alteplase, excluding upper age restriction.

RESULTS

Regardless of treatment allocation, 90-day mortality was lower among RCT patients aged ≤80 versus >80 years who otherwise met existing European regulatory criteria (246/2405 [10.2%] versus 307/1028 [29.9%], respectively). Among patients aged >80 years, alteplase versus placebo was associated with a higher proportion of good stroke outcome (modified Rankin Scale score 0-1; 99/518 [19.1%] versus 67/510 [13.1%]; P=0.0109) and similar 90-day mortality (153/518 [29.5%] versus 154/510 [30.2%]; P=0.8382). The odds of a good stroke outcome following alteplase allocation in the full RCT population were independent of age (P=0.7383). Good stroke outcome was reported for almost half (4821/11 169 [43.2%]) of the patients who received alteplase in routine practice. Outcomes in routine practice supported those achieved in RCTs.

CONCLUSIONS

Alteplase for AIS has a positive benefit-risk profile among patients aged >80 years when administered according to other regulatory criteria. Alteplase for AIS should be evaluated on an individual benefit-risk basis.

Does the Addition of Non-Approved Inclusion and Exclusion Criteria for rtPA Impact Treatment Rates? Findings in Australia, the UK, and the USA

BACKGROUND

Strict criteria for recombinant tissue plasminogen activator (rtPA) eligibility are stipulated on licences for use in ischaemic stroke; however, practitioners may also add non-standard rtPA criteria. We examined eligibility criteria variation in 3 English-speaking countries including use of non-standard criteria, in relation to rtPA treatment rates.

METHODS

Surveys were mailed to 566 eligible hospitals in Australia (AUS), the UK, and the USA. Criteria were pre-classified as standard (approved indication and contraindications) or non-standard (approved warning or researcher "decoy"). Percentage for criterion selection was calculated/compared; linear regression was used to assess the association between use of non-standard criteria and rtPA treatment rates, and to identify factors associated with addition of non-standard criteria.

RESULTS

Response rates were 74% AUS, 65% UK, and 68% USA; mean rtPA treatment rates were 8.7% AUS, 12.7% UK, and 8.7% USA. Median percentage of non-standard inclusions was 33% (all 3 countries) and included National Institutes of Health Stroke Scale (NIHSS) scores > 4, computed tomography (CT) angiography documented occlusion, and favourable CT perfusion. Median percentage of non-standard exclusions was 25% AUS, 28% UK, and 60% USA, and included depressed consciousness, NIHSS > 25, and use of antihypertensive infusions. No AUS or UK sites selected 100% of standard exclusions.

CONCLUSIONS

Non-standard criteria for rtPA eligibility were evident in all three countries and could, in part, explain comparably low use of rtPA. Differences in the use of standard criteria may signify practitioner intolerance for those derived from original efficacy studies that are no longer relevant.

Effects of alteplase for acute stroke according to criteria defining the European Union and United States marketing authorizations: Individual-patient-data meta-analysis of randomized trials

Background

The recommended maximum age and time window for intravenous alteplase treatment of acute ischemic stroke differs between the Europe Union and United States.

Aims

We compared the effects of alteplase in cohorts defined by the current Europe Union or United States marketing approval labels, and by hypothetical revisions of the labels that would remove the Europe Union upper age limit or extend the United States treatment time window to 4.5 h.

Methods

We assessed outcomes in an individual-patient-data meta-analysis of eight randomized trials of intravenous alteplase (0.9 mg/kg) versus control for acute ischemic stroke. Outcomes included: excellent outcome (modified Rankin score 0–1) at 3–6 months, the distribution of modified Rankin score, symptomatic intracerebral hemorrhage, and 90-day mortality.

Results

Alteplase increased the odds of modified Rankin score 0–1 among 2449/6136 (40%) patients who met the current European Union label and 3491 (57%) patients who met the age-revised label (odds ratio 1.42, 95% CI 1.21−1.68 and 1.43, 1.23−1.65, respectively), but not in those outside the age-revised label (1.06, 0.90−1.26). By 90 days, there was no increased mortality in the current and age-revised cohorts (hazard ratios 0.98, 95% CI 0.76−1.25 and 1.01, 0.86–1.19, respectively) but mortality remained higher outside the age-revised label (1.19, 0.99–1.42). Similarly, alteplase increased the odds of modified Rankin score 0-1 among 1174/6136 (19%) patients who met the current US approval and 3326 (54%) who met a 4.5-h revised approval (odds ratio 1.55, 1.19−2.01 and 1.37, 1.17−1.59, respectively), but not for those outside the 4.5-h revised approval (1.14, 0.97−1.34). By 90 days, no increased mortality remained for the current and 4.5-h revised label cohorts (hazard ratios 0.99, 0.77−1.26 and 1.02, 0.87–1.20, respectively) but mortality remained higher outside the 4.5-h revised approval (1.17, 0.98–1.41).

Conclusions

An age-revised European Union label or 4.5-h-revised United States label would each increase the number of patients deriving net benefit from alteplase by 90 days after acute ischemic stroke, without excess mortality.